Imagine two species of snakes that live in a tropical rain forest of Malaysia do not typically interbreed. In nature, one species is ground-dwelling and feeds mainly on insects and small amphibians near water, whereas the other snake feeds in the lower to mid-canopy of trees and vines rising from the forest floor. However, at a zoo in Singapore where they were kept in the same gallery exhibit, the two species were observed interbreeding and produced viable offspring. Which of the following reproductive barriers is most likely preventing these species from interbreeding in the forest?
In: Biology
A previous group of students wanted to investigate the factors that contribute to female fecundity (total number of eggs a female lays). They wondered if the female’s body weight might play a role. The students collected and weighed 15 newly-emerged virgin female bean beetles. Each female was mated and given plenty of black-eyed peas on which to lay eggs. Each day the students checked the beans for eggs, counted the number of eggs, and gave the female fresh beans. When the female died, the students added up the total number of eggs each female laid.
In: Biology
In: Biology
IN YOUR OWN WORDS! 100 WORDS FOR EACH QUESTION.
In: Biology
Usain Bolt, a world champion sprinter, can run a 10-meter split in 0.82 seconds. Say you obtain a quadriceps muscle sample from Usain Bolt and compare it to one from a 25-year-old male long-distance runner. What differences do you expect to observe between those two muscle samples? Select all that apply.
A) red and white muscle fibers of larger cross-sectional area in Usain Bolt's leg muscles
B) more mitochondria in Usain Bolt's leg muscles
C) more fast-twitch fibers in Usain Bolt's leg muscles
In: Biology
Oxygen plays an important role in distinguishing the lifestyles of prokaryotes. Name and describe the five modes of growth bacteria can exhibit in response to oxygen (0.5 pts for each correct lifestyle and description). Provide a bacterial species as an example for each lifestyle and list which clade it belongs to (e.g. Lysinibacillus parviboronicapiens is a Gram-positive bacteria – you won’t get credit if you use this example. 0.5 pts for each correct example and clade).
In: Biology
It may be said that it each week it takes 8000 pounds of grass to feed a small herd of zebras (which together weighs 3000 pounds). These zebras will sustain a group of lions, which together weigh 1000 pounds. Why does it take more energy stored in one level of this simple food chain to sustain the next level of the food chain? Your answer lies in the laws of thermodynamics.
In: Biology
Describe two causes of BOTH the fast and the slow phase of EPOC (excess post-exercise oxygen consumption).
In: Biology
Similarities and differences between natural, domestic, and sexual selection.
In: Biology
Please answer both questions:
1. A number of different buffers/components are used in the PCR. Explain the function of each:
DNA plasmid
Primer pair
dNTPs mixture
Taq polymerase
2. In our PCR reaction the optimum annealing temperature is 56oC. Explain the general factors that help determine the optimum annealing temperature of a PCR reaction
In: Biology
An organism that possesses all the enzymes of the EMP and Pentose Phosphate pathway
has remarkable metabolic flexibility. Consider, for example, the need that organisms have
for erythrose-4-phosphate. Devise a metabolic sequence that will accomplish net synthesis
of erythrose-4-phosphate from glucose without the accumulation of any other
intermediates. (10 points).
In: Biology
How would a variation in fatty acid chain length and saturation affect the fluidity of a membrane. Describe how a glycerophospholipid and a sphingolipid would be positioned in this membrane.
In: Biology
A female fruit fly with the recessive mutant phenotype of white eyes and miniature wings is mated with a male possessing the wild-type phenotype of red eyes and normal wings. Among the F1s, all the females are wild-type while all the males exhibit the mutant phenotype. The F2s resulting from a test cross exhibit predominantly (63%) parental phenotypes. How do you explain these results?
In: Biology
1. Please discuss briefly the design and operation of batch heat sterilization of liquids. What factors affect the sterilization time of the batch system and how does a system achieve a desired level of cell destruction?
2. Is it possible to achieve absolute sterility? Explain.
3. What are the advantages of continuous over batch sterilization of liquids.
4. Explain why for the batch sterilization design is based on the number of microorganism and not on the concentration.
Cite all references.
In: Biology